VOA慢速英语:做鬼脸对马来熊来说很有趣

mimic – v. to copy (someone or someone's behavior or speech)

wrinkle v. to cause (something) to develop wrinkles

domesticate – v. to breed or train (an animal) to need and accept the care of human beings

solitary – adj. tending to live or spend time alone

mammal – n. a type of animal that feeds milk to its young and that usually has hair or fur covering most of its skin